It's not easy to be certain, but my guess is that this is a Segestria species (tube web spider)... there are a good few brown/tan/grey spiders (such as Drassodes stone spiders, Clubiona sac spiders, mouse spiders - though the latter don't have abdominal markings) with reasonably similar features and any other shots would be handy, as would confirmation of scale...but going by the glossy cephalothorax and the long tapering line down the centre of the abdomen. If the spinnarets at the end of theabdomen are very evident then this would eliminate Segestria.